Device and method for suturing of internal puncture sites

ABSTRACT

A suture applying device comprises a shaft having a nose piece attached at its distal end. The shaft and the nose piece are separated by a transition region, and a needle entry lumen in the shaft permits a flexible needle to be introduced in the distal direction. The needle is able to cross the transition region and penetrate tissue held therein and enter into a return lumen in the nose piece. The return lumen is U-shaped and acts to bend the flexible needle as it is advanced. In this way, the needle passes from the nose piece through the transition region in a proximal direction, and is able to pass through tissue within the transition region generally on the opposite side of a tissue puncture from the first suture passage. The needle then exits from the device, permitting the suture attached to the needle to be drawn fully through the device. The suture may then be tied in order to close and seal the tissue penetration.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates generally to devices and methodsfor the percutaneous closure of body lumens. More particularly, thepresent invention relates to devices and methods for the percutaneousclosure of arterial and venous puncture sites, which are usuallyaccessible only through a tissue tract.

[0003] A number of diagnostic and interventional vascular procedures arenow performed transluminally, where a catheter is introduced to thevascular system at a convenient access location and guided through thevascular system to a target location using established techniques. Suchprocedures require vascular access which is usually established using anintroducer sheath according to the well known Seldinger technique, asdescribed, for example, in William Grossman's “Cardiac Catheterizationand Angiography,” 3rd Ed., Lea and Febiger, Pa. 86, incorporated hereinby reference.

[0004] When vascular access is no longer required, the introducer sheathmust be removed and bleeding at the puncture site stopped. One commonapproach for achieving hemostasis (the cessation of bleeding) is toapply external force adjacent to and upstream from the puncture site,typically by manual or “digital” compression. This approach suffers froma number of disadvantages. It is time-consuming, frequently requiringonehalf hour or more of compression before hemostasis is assured. It isuncomfortable for the patient and frequently requires administeringanalgesics to be tolerable. Moreover, the application of excessivepressure can at times totally occlude the underlying blood vessel,resulting in ischemia and/or thrombosis. Following manual compressionthe patient is required to remain recumbent for at least six and attimes as long as eighteen hours under close observation to assurecontinued hemostasis. During this time renewed bleeding may occurresulting in bleeding through the tract, hematoma, and/or pseudoaneurismformation as well as arteriovenous fistula formation. Thesecomplications may require blood transfusion and/or surgicalintervention. The incidence of these complications increases when thesheath size is increased and when the patient is anticoagulated. It isclear that the standard technique for arterial closure can be risky andis expensive and onerous to the patient. While the risk of suchconditions can be reduced by using highly trained individuals, such useis both expensive and inefficient.

[0005] To overcome the problems associated with manual compression, theuse of bioabsorbable fasteners to stop bleeding has been proposed byseveral groups. Generally, these approaches rely on the placement of athrombogenic and bioabsorbable material, such as collagen, at thesuperficial arterial wall over the puncture site. While potentiallyeffective, this approach suffers from a number of problems. It can bedifficult to properly locate the interface of the overlying tissue andthe adventitial surface of the blood vessel, and locating the fastenertoo far from that surface can result in failure to provide hemostasisand subsequent hematoma and/or pseudo aneurism formation. Conversely, ifthe fastener intrudes into the arterial lumen, intravascular clotsand/or collagen pieces with thrombus attached can form and embolizedownstream causing vascular occlusion. Also, thrombus formation on thesurface of a fastener protruding into the lumen can cause a stenosiswhich can obstruct normal blood flow. Other possible complicationsinclude infection as well as adverse reactions to the collagen implant.

[0006] For these reasons, it would be desirable to provide improveddevices and methods to close and seal body lumen puncture sites. Itwould be particularly desirable to provide percutaneous devices andmethods for suturing the puncture sites required for percutaneousvascular procedures.

[0007] 2. Description of the Background Art

[0008] Devices capable of delivering needles to various tissue locationsare described in the following patents and patent applications: U.S.Pat. Nos. 4,493,323 and 659,422; European patent application 140 557;and U.S.S.R patent applications 1174-036-A and 1093-329-A. Othersuturing and ligating devices are described in U.S. Pat. Nos. 3,665,926;2,959,172; and 2,646,045. Devices for sealing percutaneous vascularpenetrations using various plug and fastener structures are described inU.S. Pat. Nos. 5,222,974; 5,192,302; 5,061,274; 5,021,059; 4,929,246;4,890,612; 4,852,568; 4,744,364; 4,587,969; and 3,939,820. Collagenfastener sealing devices are under commercial development by DatascopeCorp., Montvale, N.J., and Kensey Nash Corporation, Exton, Pa. U.S. Pat.No. 4,161,951, describes a needle driver to facilitate surgicalsuturing. U.S. Pat. No. 4,317,445, discloses a catheter having an axiallumen which provides an indication of blood flow when the catheter hasbeen successfully introduced to the vascular system. A brochure entitled“Innovation Through Progress” published by REMA-Medizintechnik GmbH,Durbheim-Tuttlingen, Germany, describes a suturing device which carriesa pair of needles with a length of suture extending therebetween at itsdistal end. Features of the REMA-Medizintechnik suturing device appearto be described in DE 42 10 724. A device and method for the suturing ofvascular penetration sites are described in copending application serialno. 07/989,611, commonly assigned with the present application.

SUMMARY OF THE INVENTION

[0009] The present invention provides devices and methods for suturingtissue penetrations and puncture sites and is particularly useful forthe suturing of puncture sites distal to a tissue tract, such aspunctures formed in blood vessels to provide vascular access. Devicesaccording to the present invention will comprise a needle-guiding deviceincluding a shaft having a proximal end and a distal end and will definea needle path having an entry segment, a return segment, and an exitsegment. Using such devices, elongate flexible needles may be guidedthrough tissue on either side of a puncture site by pushing on theneedle from the entry segment. The needle will then pass through tissuecaptured in a gap or transition region between the entry segment and thereturn segment. The needle is resiliently flexed (elastically deformed)to turn back on itself as it passes through the return segment of theneedle path and is thus directed proximally into the exit segment. Theneedle thus also passes through tissue captured in the gap between thereturn segment and the exit segment, permitting suture to be drawn bythe needle through opposed sides of the puncture site. The suture maythen be tied off to close the puncture in a conventional manner.

[0010] According to a first aspect of the method of the presentinvention, the elongate flexible needle is provided and pushed inwardlyso that its distal tip penetrates through an anterior surface of thewall of a body lumen adjacent a puncture site. The flexible needle isthen resiliently flexed (elastically deformed) as it travels within theinterior of the body lumen so that the distal tip will penetrateproximally (outwardly) through a posterior surface of the luminal walladjacent the puncture site. As it emerges from the device, the needlestraightens and may be pulled outwardly to draw suture through theneedle penetrations thus formed on opposite sides of the puncture, andthe suture tied off to close the puncture site.

[0011] According to a second aspect of the method of the presentinvention, both the elongate flexible needle and a needle-guiding deviceare provided. The needle-guiding device defines the needle path havingan entry segment, a return segment, and an exit segment. Theneedle-guiding device is first introduced through a tissue tract so thata gap between the entry/exit segments and the return segment lies at thepuncture site. After the needle-guiding device is in place, the flexibleneedle may be pushed through the entry segment of the needle path sothat the needle first passes through tissue adjacent the puncture siteand into the return segment of the needle path. The needle is thenturned as it advances through the return segment so that it passesoutwardly through tissue on the other side of the puncture site and theninto the exit segment. The needle is pushed sufficiently far so that thedistal end of the needle emerges from the exit segment of the needlepath where it may be manually grasped and pulled from the needle-guidingdevice. The suture is then released from the device, the devicewithdrawn, and the suture tied to close the puncture site.

[0012] In a first aspect of the device of the present invention, thesuturing device comprises a needle-guiding device including a shafthaving a proximal end, a distal end, an entry lumen, and an exit lumen.A nose piece is attached to the distal end of the shaft and includes areturn lumen disposed to receive the flexible needle from the entrylumen and to turn the needle to enter the exit lumen as the needle isadvanced from the entry lumen. A gap between the shaft and the nosepiece receives the tissue to be sutured and exposes the tissue topassage of the suturing needle.

[0013] Typically, the nose piece will be elongated with a tapered distaltip and will have a circular cross-section having a maximum peripherallength which is generally equal to that of a transition region whichdefines a tissue-receiving gap between the nose piece and the shaft. Ina preferred embodiment, the nose piece will be fixed relative to theshaft. In an alternate embodiment, the nose piece will be rotatablerelative to the shaft. In either case, it will be necessary for the nosepiece to align the entry and exit ports of the return lumen to receivethe needle from the entry lumen and direct the needle to the exit lumen.

[0014] In another aspect of the device of the present invention, guidetubes are provided together with a mechanism to selectively extend theguide tubes across the tissuereceiving gap between the entry lumen andthe entry port of the return lumen and between the exit port of thereturn lumen and the exit lumen. The needle guide tubes help assure thatthe flexible needles will not become misaligned during passage throughtissue across the gap between the shaft and the nose piece.

[0015] In another particular aspect of the present invention, the devicefurther comprises a drive wheel on the shaft disposed to engage aflexible needle present in the entry lumen. In this way, even veryflexible needles (lacking substantial column strength) can be advancedthrough the entry lumen to the return lumen and subsequently to exitlumen. The present invention still further provides a suturing kitincluding a needle-guiding device, as described above, in combinationwith a flexible needle attached to a length of suture. The needle willhave a length sufficient to permit its introduction through the entrylumen, return lumen, and exit lumen, so that the needle may be advancedby pushing on the needle within the entry lumen until a distal end ofthe needle emerges from the exit lumen. In this way, a user can advancethe needle entirely through the needle-guiding path, and grasp theneedle once it is emerged from the exit lumen, either manually or usinghemostats. Preferably, the needle will be from 10 cm to 30 cm in length.The needle may then be withdrawn from the needle-guiding device and thesuture released from the device. After the device is withdrawn from thetissue tract, the suture may be tied off in a conventional manner.

[0016] The present invention further comprises kits including the needleguiding device, the needle, and suture. Conveniently, all threecomponents can be packaged together in sterile packaging, such as asterile flexible pouch.

[0017] The devices and methods of the present invention are usefulwherever it is desired to place a tied suture loop to close a tissuepuncture site, particularly a puncture site through the wall of a bodylumen, and more particularly a percutaneous vascular puncture site atthe distal end of a tissue tract. The devices and methods can achieveclosure wholly within the tissue tract leading to a puncture site andcan be manipulated entirely from the portion of the device lying outsideof the tissue tract. The present invention will find its greatest use inthe sealing of a femoral artery cannulation site made in connection withpercutaneous transluminal procedures such as angiography, angioplasty,atherectomy, laser ablation, stent placement, intravascular drugdelivery, intravascular imaging, and the like. The present inventionwill also find use in other medical procedures which rely onpercutaneous access to hollow body organs and lumens, such aslaparoscopic procedures, endoscopic procedures, artheroscopicprocedures, and the like.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018]FIG. 1 is a perspective view of a suturing device constructed inaccordance with the principles of the present invention.

[0019]FIG. 1A illustrates a flexible suturing needle attached to alength of suture, which needle and suture may be introduced using thesuturing device of FIG. 1.

[0020]FIG. 1B illustrates an alternative distal end configuration forthe suturing device of FIG. 1.

[0021]FIG. 2 is an elevational view of the suturing device of FIG. 1,with portions broken away.

[0022]FIG. 3 is a detailed view of the distal end of the suturing deviceof FIG. 1, with portions broken away.

[0023]FIG. 3A is a cross-sectional view taken along line 3A-3A of FIG.3.

[0024]FIG. 3B is a cross-sectional view taken along line 3B-3B of FIG.3.

[0025]FIG. 4A is a detailed view similar to FIG. 3, illustrating therelease of suture from the distal end of the device.

[0026]FIG. 4B is a cross-sectional detail of FIG. 4A illustrating asuture-release slot of the present invention.

[0027] FIGS. 5A-5C illustrate the suturing device in its initialconfiguration prior to extension of needle guide tubes and advancementof a suturing needle.

[0028] FIGS. 6A-6C illustrate the suturing device in an intermediateconfiguration after the needle guide tubes have been advanced but priorto advancement of the suturing needle within the needle guide path.

[0029] FIGS. 7A-7C illustrate the suturing device with the needle guidetubes advanced and the suturing needle partially advanced through theneedle guide path by a needle drive wheel.

[0030]FIG. 8 is a detailed view illustrating the distal end of theneedle-guiding device placed within a puncture in the femoral arteryprior to advancement of the needle guide tubes.

[0031] FIGS. 9-12 illustrate successive steps of advancing the suturingneedle within the needle-guide path of the needleguiding device indetail.

[0032]FIG. 13 illustrates a tied suture loop applied by the device inthe method of the present invention.

[0033] FIGS. 14A-14C illustrate an alternative arrangement of the distalend of the needle-guiding device of the present invention, where arotatable nose piece carrying a pair of return lumens is provided forreceiving a pair of needles from the guide shaft.

[0034]FIGS. 15A and 15B illustrate placement of single and double sutureloops using the first and second embodiments of the present invention.

[0035]FIGS. 16A and 16B illustrate an alternative suture releasemechanism where a portion of the nose piece slides to expose the returnlumen.

[0036]FIGS. 17A and 17B illustrates a second alternative suture releasemechanism, where a portion of the nose piece swings open to expose thereturn lumen and release the suture.

DESCRIPTION OF SPECIFIC EMBODIMENTS

[0037] Referring now to FIGS. 1-3, 3A, and 3B, a suture applying device10 which is suitable for suturing and sealing of a percutaneous vascularpuncture site, particularly punctures made to the femoral artery in apatient's groin, will be described. It will be appreciated, however,that the device of the present invention can be readily adapted for usewith punctures made to other hollow body organs and lumens, although itmay be necessary to modify the dimensions and other particular aspectsof the device to accommodate a different usage environment.

[0038] The suture applying device 10 of the present invention comprisesan elongate shaft 12 having a nose piece 14 at its distal end and ahandle 16 at its proximal end. The shaft is illustrated as an elongatecylindrical rod having a plurality of axial lumens formed therein, butcould also comprise a variety of other geometries which are able tofulfill the essential requirements of the shaft, i.e., defining a needleguide path from its proximal end to its distal end and again back fromthe distal end to the proximal end. The shaft will usually also includeor otherwise define a guide wire lumen (particularly for vascularapplications), and a blood pressure detection lumen. Each of theseaspects will be described in more detail with regard to the exemplaryembodiment of FIGS. 1-3.

[0039] Shaft 12 includes a needle entry lumen 18 terminating at a needleexit port 20 at its distal end and a needle exit lumen 22 which beginswith a needle entry port 24 at its distal end. The shaft 12 furtherincludes a guide wire lumen 26 which extends through the nose piece 14and a blood pressure detection lumen 28 having a blood inlet port 30 atits distal end. The blood inlet port 30 is located within a transition(gap-defining) region 32 between the nose piece 14 and shaft 12, as willbe described in more detail hereinafter.

[0040] The nose piece 14 includes a needle return lumen 36 which ispreferably a U-shaped lumen having a needle entry port 38 aligned withneedle exit port 20 of the needle entry lumen 18 and a needle exit port40 aligned with needle entry port 24 of the needle exit lumen 22. Inthis way, a flexible needle 42 (FIGS. 1A and 3) entering through theentry lumen 18 will be able to pass across the gap defined by thetransition region 32 and into the needle return lumen 36 (in some casesthrough a needle guide tube as described in connection with FIG. 3hereinafter) where its direction of travel will be reversed from thedistal direction to the proximal direction. The needle 42 will thenemerge from the needle exit port 40 of return lumen 36 and be able toenter the needle exit lumen 22 through aligned needle entry port 24.Thus, tissue disposed in transition region 32, i.e., the gap between thedistal end of shaft 12 and the proximal end of nose piece 14, will bepenetrated by the flexible needle 42 on opposite sides of a puncturesite, as will be described in greater detail hereinafter.

[0041] In the suturing of a puncture site in the wall of a body lumen,and in particular the wall of a blood vessel, it is desirable tominimize and preferably eliminate any tearing or enlarging of thepuncture during the suturing procedure. With the device of the presentinvention, however, it will also be desirable to distend the peripheryof the puncture so that its edges are extended along an axis transverseto that of the blood vessel. In this way, opposed edges of the puncturewill be exposed to the needle as it passes through the transition region32 between the nose piece 14 and the shaft 12. In order tosimultaneously achieve both these objectives, i.e., distending the edgesof the puncture without tearing, and further provide a nose piece 14having sufficient size to space the entry and exit ports of the returnlumen 36 sufficiently far apart to be aligned with needle ports 20 and24, the geometry of the nose piece 14 and of the transition region 32are selected to properly configure and conform the edges of the luminalpuncture as the suture applying device 10 is introduced therethrough.

[0042] In particular, the nose piece 14 will be tapered from asmall-diameter, generally circular distal tip 50 to a proximal portionor length 52 having a generally oval configuration, as best illustratedin FIGS. 3 and 3A. In the illustrated embodiment, the nose piece 14 isgenerally conical until a circular junction 53 is reached. The proximalportion 52 of the tip makes a transition from a circular cross-sectionat 53 to an oval cross-section at 55. The particular dimensions of thetip will be selected based on the intended use of the device 10. For thesuturing and sealing of the femoral artery, the distal tip 50 willtypically have a diameter from about 0.25 mm to 1 mm, typically beingjust large enough to receive the guide wire GW into the guide wire lumen26. The maximum dimensions of the oval-shaped proximal portion at 55will be in the range from 2 mm to 4.5 mm (major diameter) and in therange from 1 mm to 2.25 mm (minor diameter). In particular the majordiameter will be selected to permit the needle entry port 38 to besufficiently spaced-apart from the needle exit port 40 to provide adesired distance between the entry and exit penetrations of the suturingneedle through the tissue surrounding the luminal puncture. The ovalcross-section of the proximal end 55 of the proximal portion 52 is thusdesirable since it minimizes the total peripheral length about the nosepiece which must pass through the luminal wall puncture while maximizingthe distance between the entry port 38 and exit port 40, as justdescribed. In this way, proper spacing of the needle passages throughthe tissue will be provided with minimum stretching or enlargement ofthe luminal penetration.

[0043] The geometry of the transition region 32 will also be chosen toprovide for proper manipulation and positioning of the tissuesurrounding the luminal puncture site with minimum distending (andpreferably no tearing) of the edges of the puncture site. In theembodiment of FIGS. 1-3, the transition region 32 will conform at itsdistal end to the oval shape of the proximal end 55 of the proximalportion 52 of nose piece 14. The cross-sectional orientation of thetransition region 32 changes in the proximal direction, eventuallybecoming an oval 57 having its major axis disposed orthogonally (i.e. at90°) relative to the major axis of the proximal portion 52 of nose piece14 (FIG. 3B). The oval cross-section of the transition region 32 willrotate 90° from the position at 55 to the position at 57. That is, theperipheral shape and distance will remain constant, but the orientationof the major axis will turn through 90° over the axial length of thetransition region. By maintaining a constant total peripheral lengtharound the transition region at all points (e.g., equal to the outerdiameter of the introducer sheath which had been used in performing theintravascular procedure and removed prior to suturing), the luminalpenetration is held firmly and turned to the desired orientation withoutfurther distending or tearing.

[0044] An alternative nose piece 15 configuration for the suturingdevice 10 is illustrated in FIG. 1B. The nose piece 15 comprises atapered distal tip 51, a generally cylindrical shank portion 53, and aproximal portion 55A (which is similar to the proximal portion 52 of theprevious embodiment). A needle return lumen 59 is formed in the proximalportion 55A and is generally identical to the lumen 42 described above.The nose piece 15 will be longer than the nose piece 14, typicallyhaving a length in the range from 15 cm to 30 cm, usually about 20 cm.The purpose of the longer nose piece 15 is to allow the suturing device10 to be partially withdrawn from the luminal puncture. By partiallywithdrawing the device 10, the suture can be released from the nosepiece, and the suture partly tightened prior to total withdrawal of thedevice. In this way, the puncture can be at least partly closed by thesuture prior to removal of the device, and hemostasis can be maintainedto limit blood loss prior to complete closure of the puncture.

[0045] Usually, both the tapered distal tip 51 and the shank 53 willhave circular cross-sections, with the peripheral length of the shankbeing uniform along its length and generally equal to the maximumperipheral length of the nose piece, usually having a diameter equal tothat of the introducer sheath which had previously been in place in thepuncture. The proximal end portion 55 serves as a transition from thecircular peripheral shape of the shank 53 to an oval transition region59, which will generally be identical to the transition region 32 indevice 10.

[0046] The remaining description herein will refer specifically todevices 10 having the nose piece 14 illustrated in FIGS. 1, 2, 3, etseq, but it will be appreciated that such description applies as well todevices incorporating nose piece 15.

[0047] The suturing needle 42 and attached suture 62 are illustrated indetail in FIG. 1A. Suturing needle 42 will be formed from a highlyflexible material which will be able to pass through the radius ofreturn lumen 36. Typically, the turn radius will be in the range fromabout 1 mm to 2.25 mm, and the needle 42 will have to be able to passthrough this radius without undergoing substantial permanent(non-elastic) deformation which would cause binding or jamming as theneedle passes outward from the return lumen 42. Preferably, the needle42 will be formed from stainless spring steel or a superelasticmaterial, typically nickel titanium alloy. Preferred superelastic nickeltitanium alloys are available commercially from suppliers, such as ShapeMemory Applications, Sunnyvale, Calif., Innovative TechnologiesInternational, Beltsville, Md. and Fort Wayne Metals, Fort Wayne, Id.The diameter of the needle will typically be from about 0.2 mm to 0.5mm, and the length will be sufficient to permit the needle to beadvanced through the entry lumen 18, across the return lumen 36, andoutward through the exit lumen 20, while the needle is being pushed froma location at or near the proximal end of the entry lumen. Typically,the needle will have a length in the range from about 10 cm to 30 cm,preferably in the range from about 15 cm to 20 cm. The needle will beattached to a length of suture, typically from about 50 cm to 100 cm,usually at the proximal end of the needle. Particular methods forforming needles and attaching needles to suture are well known in theart.

[0048] Referring now to FIGS. 4A and 4B, in a preferred embodiment ofthe present invention, suture 62 (FIG. 1A) will be released from thenose piece 14 through a suture-release slot 60. The needle return lumen36 in nose piece 14 will have a diameter which is large enough toreceive the flexible needle 42 with a clearance in the range from 0.03mm to 0.1 mm. The width of the suture-release slot 60, however, will beless than the diameter of the flexible needle 42, typically from 0.1 mmto 0.35 mm. In this way, the needle will travel through the return lumen36 and will not be able to escape through the suture-release slot 60.Suture 62 which is attached to the butt end of the flexible needle 42will be sufficiently small to pass through the suture-release slot 60.Thus, after the needle 42 has passed entirely through the needle returnlumen 36 and into the needle exit lumen 22 in shaft 12, the suture 62will pass out of the nose piece 14 through the suture release slot 60,as illustrated in steps (1), (2), and (3) in FIG. 4A. The suture 62 willthus directly engage the posterior side of the tissue to be sutured,leaving the nose piece 14 free to be withdrawn through the luminalpuncture without entanglement with the suture 62. FIG. 4B illustrates aproximal or trailing end 64 of the flexible needle 62 as it passesthrough the needle return lumen 36. As can be seen, the suture 62 passesinto the suture-release slot 60 as it is drawn through the return lumen36 by the needle 42. Alternative suture-release mechanisms will bedescribed in connection with FIGS. 16A, 16B, 17A, and 17B, hereinafter.

[0049] In a preferred aspect of the present invention, the nose piece 14will include a soft tip 66 to facilitate entry into the body lumen beingsutured. Conveniently, the soft tip 66 can be formed from a softpolymer, such as a polyether block amide, e.g., Pebax®. The soft tip 66can be joined to the more rigid proximal portion of the nose piece 14 byany conventional manner. In all other ways, the soft tip can form acontinuous structure with the proximal portion of the nose piece 14. Theproximal portion of nose piece 14, the transition region 32, and theshaft 12, will typically be formed from a relatively rigid polymer(e.g., polycarbonate) or a metal (e.g., stainless steel) by conventionalmethodologies, such as extrusion, molding, machining and the like. Thedifferent portions of the device may be formed in separate pieces, andjoined later, e.g. by the use of adhesives, heat bonding, mechanicalattachment, or the like.

[0050] Referring now to FIGS. 1, 2, and 5A-5C, a needle guide andadvancement mechanism constructed in accordance with the principles ofthe present invention will be described. The needle guide andadvancement mechanism includes an entry guide tube 70 and an exit guidetube 72, each being secured at its proximal end in a guide tube yoke 74.The guide tubes 70 and 72 are slidably received in the needle entrylumen 18 and needle exit lumen 22, respectively, so that axialtranslation of the guide tube yoke 74 (as described hereinafter) canadvance the distal ends of the guide tubes across the gap defined by thetransition region 32 (as illustrated in FIG. 3 and described in moredetail in connection with FIG. 6A-6C). The guide tube yoke 74, in turn,is slidably mounted in a spring retainer 76, with a spring 78 beingdisposed therebetween. As illustrated in FIGS. 5A and 5B, spring 78 isin compression, with the entire assembly of the guide tubes 70 and 72and guide tube yoke 74 being in a retracted configuration, i.e. fully tothe left in FIGS. 5A and 5B.

[0051] A yoke-release mechanism comprises a thumb lever 80 extendingfrom handle 16 and a latch member 82 which captures the guide tube yoke74 through an extension 84. The thumb lever 80 and latch member 82 arepivotally mounted within the handle and are operatively connectedthrough a pin and slot 86 so that depression of thumb lever 80 in thedirection of arrow 88 will release the guide tube yoke extension 84, asillustrated in FIG. 6A-6C. In this way, spring 80 will decompress totranslate the guide tube yoke 74 distally, i.e. toward the right, asillustrated in FIGS. 6A-6C.

[0052] The entry guide tube 70 will carry the flexible suture needle 42with a sharpened-distal tip 90 projecting just out of the distal end ofthe tube, as illustrated in FIGS. 5A and 5C. In this way, the needle 42will fill the lumen of the guide tube 70 and prevent tissue fromentering the lumen as the guide tube is advanced. The exit guide tube 72will have a stylet 92 (or other obturator) filling its axial lumen. Asillustrated in FIGS. 5A and 5C, the stylet 92 will preferably also havea sharpened distal tip 94 which projects outwardly from the distal endof the guide tube as the guide tube is advanced. The purpose of thestylet 92 is to prevent tissue from entering (and blocking) lumen ofguide tube 72 as it is advanced through the tissue. After the exit guidetube 72 has been advanced across the transition region 32, the stylet 92will be withdrawn leaving the lumen of the guide tube open and availablefor advancement and passage of the flexible needle 42, as will bedescribed in greater detail in connection with FIGS. 7A-7C.

[0053] Referring now in particular to FIGS. 1, 2, and 5A-5C, theexemplary needle guide and advancement mechanism for use with the deviceof the present invention further comprises a drive wheel 100 rotatablymounted in yoke 102. The yoke 102, in turn, is attached to the interiorof handle 16 on a spring mount 104. Spring mount 104 urges the drivewheel 100 against flexible suture needle 42 in a manner described morefully in connection with FIG. 6A-6C. Preferably, the periphery 106 ofthe drive wheel 100 is serrated or otherwise roughened to enhancefrictional coupling between the drive wheel and the needle 42 tofacilitate advancement.

[0054] Drive wheel 100 is driven by a rack 110 which engages pinion gear112 which is coaxially mounted and attached to the drive wheel. The rack110, in turn, is actuated by a lever 114 which is pivotally attached tothe handle 16. A mechanism (not illustrated) will usually be providedfor biasing the rack 110 against the pinion gear 112. For example, aleaf spring could be provided within the yoke to upwardly bias the rack110 against the pinion gear 110. Alternatively, a torsion spring couldbe provided at the pivot 116 connecting the rack 110 to the lever 114.

[0055] The drive wheel 100 is actuated by manually squeezing the lever114 toward the handle 16 in the direction of arrow 118. It will bepossible to select the relative diameters of the drive wheel 100 and thepinion gear 112 and the length and pivot point of the rack so that asingle stroke of the lever 114 can fully drive the needle through thetarget tissue, return lumen 36, and needle exit lumen 22, so that theneedle can be manually grasped or mechanically captured, e.g., usinghemostats, as it emerges from the exit lumen. Alternatively, a mechanism(not illustrated) could be provided to permit multiple, sequentialactuation of the lever 114 in order to drive the needle the requisitedistance.

[0056] The suture applier 10 is illustrated in its “shelf” configurationin FIGS. 2 and 5A-5C. That is, the needle guide tubes 70 and 72 arefully retracted, i.e. drawn to the left in each of these figures. Bydepressing thumb lever 80, the user releases the guide tube yoke 74,thus driving the guide tubes in the distal direction as indicated byarrows 120 in FIG. 6A. Such movement of the entry guide tube 70 alignsan elongate cutout 122 in the guide tube with the periphery of drivewheel 100, as best illustrated in FIG. 6B. In this way, the drive wheel100 directly engages the side of the suture needle 42 which is exposedthrough the cutout 122. At this moment, the guide tubes will also extendacross the transition region 32 and seat into the return lumen 36 in thenose piece 14. The stylet 92 may then be withdrawn in order to open thelumen of the exit guide tube 72 so that it is free to receive the sutureneedle.

[0057] After the stylet 92 is withdrawn, the needle 42 may be advancedby the needle advance mechanism, as illustrated in FIG. 7A-7C. The lever114 is manually closed in the direction of arrow 130 to translate rack110 across the pinion gear 112. This motion causes drive wheel 100 torotate clockwise in the direction of arrow 132. As the drive wheel 100is engaging suture needle 42 through the cutout 122, the needle will bemoved in the distal direction (arrow 134) causing the sharpened tip 90to advance and cross the gap defined by transition region (arrow 136),through the return lumen 36 and back through the transition region gap(arrow 138). The needle advancement mechanism will be actuatedsufficiently (or for a sufficient number of times) to advance the needle42 so that its distal end 90 emerges from the proximal end of the device10, as illustrated in broken line in FIG. 7A. The needle may then begrasped or captured and withdrawn from the device 10 in order to drawthe suture through the device and the tissue to be sutured, as will bedescribed in more detail hereinafter.

[0058] It would also be possible to modify the drive wheel 100 advancemechanism to engage and advance the guide tube 70 so that the guide tubecould be advanced by an initial portion of the stroke of lever 114.Guide tube 70 could be coupled to guide tube 72 through a yoke similarto the yoke 74, but no spring 78 or yoke-release mechanism would berequired. A variety of particular mechanisms for advancing the guidetubes and/or needles would be available within the scope of the presentinvention.

[0059] Referring now to FIG. 8-13, use of the device 10 for applying endtying a suture loop in a blood vessel BV wall will be described indetail. Referring in particular to FIG. 8, the device 10 is introducedthrough an existing tissue tract T, typically formed by an introducersheath which has been previously placed in connection with aconventional intravascular therapeutic or diagnostic procedure, such asangiography, angioplasty, atherectomy, laser ablation, cardiac mapping,cardiac ablation, or the like. The introducer sheath is removed prior tointroduction of the nose piece 14 of the suturing device 10. Asdiscussed above, the maximum peripheral length of the nose piece 14 willgenerally be the same as the circumferential length of the introducersheath so that the penetration is not torn but remains blocked oroccluded by the device to reduce blood loss.

[0060] The device 10 is introduced with the needle guide tubes 70 and 72fully retracted in the proximal direction and with the stylet 92 inplace in the lumen of the exit guide tube 72. The device 10 ispositioned over the previously placed guide wire GW and introducedsufficiently so that the gap defined by the transition region 32receives the edges of the puncture P. Conveniently, proper positioningof the device 10 can be confirmed by detecting the flow of blood intoblood inlet port 30 and as it appears at the open proximal end of lumen28.

[0061] After the device 10 has been properly positioned, as illustratedin FIG. 8, the needle guide tubes 70 and 72 will be advanced across thegap defined by the transition region 32, as illustrated in FIG. 9. Theneedle advancement mechanism, as previously described, will be used toeffect the advance. Each guide tube 70 and 72 will pass through tissuewhich is located within the transition region 32. The presence of theflexible needle 42 in guide tube 70 prevents “coring” of the tissue intothe guide tube 70. Similarly, the presence of stylet 92 in needle guidetube 72 prevents such coring.

[0062] The stylet 92 is next withdrawn, leaving the lumen of the needleguide tube 72 empty and available to receive flexible needle 42, asillustrated in FIG. 10.

[0063] The flexible needle 42 is next advanced across the U-shapedreturn lumen 36 and into the needle return guide 72, as illustrated inFIG. 11. Note that the highly flexible nature of the needle togetherwith the close fit between the needle, guide tubes 70 and 72, and returnlumen 32, permits it to turn across the small radius and advance withbuckling in spite of the frictional and bending forces opposing theneedle's advance. The needle continues to be advanced until thesharpened distal tip 90 emerges from the device 10 (as illustratedpreviously in FIG. 7A). After it emerges, the needle tip 90 may begrasped and pulled through the device 10, drawing the suture 62 throughthe return lumen 36. The needle guide tubes 70 and 72 will be withdrawn,permitting the suture to be drawn outward from the nose piece throughthe suturerelease slot 60, as illustrated in FIGS. 4A-4B and 12 (wherethe outer portion of slot 60 is shown broken away). After the suture hasbeen'released from the nose piece 14, the device 10 may be partially ortotally withdrawn, leaving the suture accessible for tying of a knot Kto close the puncture wound, as illustrated in FIG. 13.

[0064] When using a device 10 having an elongated nose piece 15, asillustrated in FIG. 1B, it will be preferred to only partially withdrawthe device so that the shank portion 53 remains within the penetrationP. As the shank 53 will preferably have a perimeter substantially equalto that of the introducer sheath previously in place, the shank will beable to occlude the puncture to inhibit blood loss, without distendingthe puncture. The extra length provided by shank 53 permits the nosepiece 15 to be withdrawn sufficiently to release the suture 62 whilestill occluding the penetration P. The knot K can thus be tied andpartially tightened prior to total withdrawal of the device 10, allowingvery rapid closure of the penetration by tightening the suture.

[0065] Referring now to FIGS. 14A-14C an alternative embodiment of anose piece 200 is illustrated. Nose piece 200 is mounted on an axial rod202 which permits it to be rotated between an aligned position, asillustrated in FIG. 14B, and a transverse position, as illustrated inFIGS. 14A and 14C. When in the aligned position of FIG. 14B, the nosepiece has an oval cross-section which gradually increases in size andwhich forms a smooth and continuous surface with the transition region204, facilitating introduction of the device through a tissue puncture.The peripheral length of the oval section is matched with thecircumference of the introducer sheath used in the initialinterventional or diagnostic procedure to minimize distending of thetissue around the luminal puncture site. In the configuration of FIG.14B, the return lumens 208 and 210, however, are out of rotationalalignment with the needle entry lumens 212 and 214 and needle exitlumens 216 and 218. Therefore, prior to needle advancement, the needleentry and exit lumens will be properly aligned with the needle returnlumens in the nose piece 200 by rotating the nose piece 200 by 90° tothe position of FIGS. 14A and 14C. The nose piece 200 will then berotated back to the aligned configuration of FIG. 14B after suturerelease from the nose piece 200 and prior to withdrawal of the devicefrom the tissue tract.

[0066] As can be seen in FIGS. 15A and 15B, the embodiment of FIGS. 1-7can be used to form a single suture loop where the nose piece 14 has arelatively small peripheral length (as illustrated on the right-handhalf of each figure). The embodiment of FIGS. 14A-14C is particularlyuseful for forming pairs of suture loops, as illustrated on theleft-hand side of each of FIGS. 15A and 15B. Of course, the embodimentof FIGS. 1-7 could be readily adapted to place two suturessimultaneously, while the nose cone of FIGS. 14A-14C could be modifiedto place only a single suture.

[0067] Referring now to FIGS. 16A and 16B, a first alternative suturerelease mechanism is illustrated. A nose piece 300 includes a slidingcover 302 which may be moved from the covered configuration (FIG. 16A)to the uncovered configuration (FIG. 16B) by sliding the coverproximally, as illustrated by arrow 304. When the cover is movedproximally, return lumen 308 is exposed, permitting the suture 62 toexit from the lumen, as illustrated by arrows 310.

[0068] A second suture release mechanism is illustrated in FIGS. 17A and17B. The mechanism is similar to that illustrated in connection withFIGS. 16A and 16B, except that cover 400 on nose piece 402 is pivotallyattached to open as illustrated in FIG. 17B. Suture 62 can thus bereleased from the return lumen 404, as illustrated by the arrows 406.

[0069] Although the foregoing invention has been described in detail forpurposes of clarity of understanding, it will be obvious that certainmodifications may be practiced within the scope of the appended claims.

What is claimed is:
 1. A method for suturing a puncture site in the wallof a body lumen, said method comprising: providing at least one elongateflexible needle having a distal tip and an attached length of suture;pushing the needle so that the distal tip penetrates inwardly through ananterior surface of the wall adjacent to the puncture site and entersinto the body lumen, whereby an inward penetration is formed;elastically bending the needle as it travels within the body lumen sothat the distal tip penetrates outwardly through a posterior surface ofthe wall adjacent to the puncture site, whereby an outer penetration isformed; pulling the needle outwardly to draw suture through the inwardand outward penetrations formed by the needle; and tying the suture toclose the puncture site.
 2. A method as in claim 1, wherein the needleis pushed by engaging a drive wheel against the needle and rotating thedrive wheel.
 3. A method as in claim 1, wherein the needle iselastically bent by travelling through a U-shaped guide path.
 4. Amethod as in claim 1, wherein the needle is pulled from the outwardpenetration.
 5. A method for suturing a puncture site distal to a tissuetract, said method comprising: providing an elongate flexible needlehaving a distal tip and an attached length of suture; providing aneedle-guiding device which defines a needle path having an entrysegment, a return segment, and an exit segment, wherein the entry andexit segments are separated from the return segment by a gap;introducing the needle-guiding device through the tissue tract so thatthe gap lies at the puncture site; pushing the needle through the entrysegment of the needle path so that the needle passes through tissueadjacent the puncture, into the return segment, through tissue on theother side of the puncture site, and then into the exit segment; pullingthe needle outwardly from the exit segment of the needle path to drawsuture from the needle-guiding device; and tying the suture to close thepuncture site.
 6. A method as in claim 5, wherein the needle is composedof a superelastic alloy.
 7. A method as in claim 5, wherein theneedleguiding device has a tapered, soft distal end to facilitateintroduction through the tissue tract and into puncture site.
 8. Amethod as in claim 7, wherein the tapered distal end has a generallyoval cross-section adjacent the transition region with the returnsegment being a U-shaped lumen disposed in a plane parallel to the majoraxis of the oval.
 9. A method as in claim 8, wherein the needleguidingdevice includes a transition region in the gap between the entry andexit segments and the return segment, wherein the transition region hasa generally oval cross-section with a major axis oriented orthogonallyrelative to the major axis of the oval portion of the tapered distalend, whereby the puncture site will be conformed to expose tissueadjacent the puncture site within the gap between the entry and exitsegments and the return segment.
 10. A method as in claim 9, wherein themaximum peripheral length around the oval cross-section of the tapereddistal end is generally equal to the maximum peripheral length aroundthe cross-section of the transition region.
 11. A method as in claim 10,further comprising withdrawing an introducer sheath from the tissuetract prior to introducing the needle-guiding device, wherein themaximum peripheral length is substantially equal to the circumference ofthe introducer sheath.
 12. A method as in claim 5, wherein theneedleguiding device includes a shank, a transition region, and a nosepiece which is rotatable about a longitudinal axis relative to the shankand transition region wherein the entry and exit segments are disposedin the shank and the return segment is disposed in the nose piece, andwherein the nose piece and transition region is a continuous ovalsurface when the nose piece and transition region are rotationallyaligned, further comprising rotating the nose piece out of alignmentwith the transition region after the needle-guiding device has beenintroduced in order to align the entry and exit lumens with the returnlumen in the nose piece.
 13. A method as in claim 5, further comprisingextending needle guide tubes across the gap between the entry and exitsegments and the return segment after the needleguiding device has beenintroduced through the tissue tract.
 14. A method as in claim 5, whereinthe needle is pushed by engaging a drive wheel against the needle androtating the drive wheel.
 15. A method as in claim 5, wherein the needleis pulled outwardly from the tissue tract.
 16. A method as in claim 5,wherein the needleguiding device is introduced over a guide wire whichis in place in the tissue tract.
 17. A method as in claim 5, wherein theneedleguiding device has an elongated nose piece and the nose pieceremains within the puncture site to occlude blood flow after the sutureis withdrawn from the suture path until the suture is tied to close thepuncture site.
 18. A suturing device comprising: a shaft having aproximal end, a distal end, an entry lumen, and an exit lumen; and anose piece attached to the distal end of the shaft and having a returnlumen disposed to receive a flexible needle from the entry lumen and toturn the needle to enter the exit lumen, wherein a gap between the shaftand a proximal end of the nose piece receives tissue to be sutured. 19.A suturing device as in claim 18, wherein the gap between the shaft andthe nose piece is defined by a transition region having a generally ovalcross-section.
 20. A suturing device as in claim 19, where the nosepiece is tapered with an oval cross-section over at least a portion ofits proximal length, wherein the maximum peripheral distance around thenose piece at its proximal end is generally equal to that around thetransition region.
 21. A suturing device as in claim 20, wherein thenose piece comprises a tapered distal tip, a shank portion having acylindrical cross-section with a circumference generally equal to themaximum peripheral length, and a proximal end piece which changes to anoval cross-section having a constant peripheral length generally equalto the maximum peripheral length.
 22. A suturing device as in claim 20,wherein the nose piece is fixed relative to the shaft.
 23. A suturingdevice as in claim 20, further comprising means for rotating the nosepiece relative to the shaft and transition region.
 24. A suturing deviceas in claim 18, further comprising needle guide tubes disposed in theentry and exit lumens and means to extend the guide tubes across the gapand to the return lumen in the nose piece.
 25. A suturing device as inclaim 18, further comprising a drive wheel disposed on the shaft toengage a flexible needle present in the entry lumen, whereby rotation ofthe drive wheel advances the needle through the entry lumen, across thegap, through the return lumen, across the gap, and through the exitlumen.
 26. A suturing device as in claim 18, wherein the nose piece hasa suture-release slot formed contiguously with the return lumen.
 27. Asuturing device as in claim 18, further comprising means for opening thenose piece to release suture therefrom.
 28. A suturing device as inclaim 27, wherein the opening means slides a portion of the nose pieceto expose the return lumen.
 29. A suturing device as in claim 27,wherein the opening means swings a portion of the nose piece to exposethe return lumen.
 30. A suturing device comprising: a shaft having aproximal end and a distal end; and means on the shaft for defining aneedle path having an entry segment, a return segment, and an exitsegment, wherein the entry and exit segments are separated from thereturn segment by a gap which receives tissue to be sutured.
 31. Asuturing device as in claim 30, further comprising means on the shaftfor advancing a needle through the needle path.
 32. A suturing device asin claim 30, further comprising means for extending needle guide tubesacross the gap between the entry segment and the return segment andbetween the return segment and the exit segment.
 33. A suturing deviceas in claim 30, wherein the shaft includes a body portion, a transitionregion, and a nose piece, wherein the entry and exit segments of theneedle path comprise lumens within the body portion, the return segmentcomprises a U-shaped lumen within the nose piece, and the transitionregion defines the gap.
 34. A suturing device as in claim 33, whereinthe nose piece is fixed relative to the body portion and wherein thenose piece and transition region have similar but orthogonally disposedoval cross-sections.
 35. A suturing device as in claim 33, furthercomprising means for rotating the nose piece about a longitudinal axisrelative to the body portion.
 36. A suturing kit comprising: a suturingneedle including an elongate needle shank having a distal tip, saidshank being composed of a flexible metal alloy; and a length of sutureattached to the needle shank; and a needle-guiding device including ashaft having a proximal end, a distal end, an entry lumen, and an exitlumen; and a nose piece attached to the distal end of the shaft andhaving a return lumen disposed to receive the suturing needle from theentry lumen and to turn the needle to enter the exit lumen, wherein agap between the shaft and the nose piece receives tissue to be sutured.37. A suturing kit as in claim 36, wherein the shank of the suturingneedle has a length which is sufficient to extend through the entrylumen, return lumen, and exit lumen so that the shank may be pushed fromthe entry lumen until the distal tip emerges from the exit lumen.
 38. Asuturing kit as in claim 37, wherein the shank of the suturing needlehas a length from 10 cm to 30 cm.
 39. A suturing kit as in claim 36,wherein the gap between the shaft and the nose piece is defined by atransition region having a generally oval cross-section.
 40. A suturingkit as in claim 39, where the nose piece is tapered with an ovalcross-section at its proximal end, wherein the maximum peripheral lengtharound the nose piece is generally equal to that around the transitionregion.
 41. A suturing kit as in claim 40, wherein the nose piececomprises a tapered distal tip, a shank portion having a cylindricalcross-section with a circumference generally equal to the maximumperipheral length, and a proximal end piece which changes to an ovalcross-section having a constant peripheral length generally equal to themaximum peripheral length.
 42. A suturing kit as in claim 31, whereinthe nose piece is fixed relative to the shaft.
 43. A suturing kit as inclaim 40, further comprising means for rotating the nose piece relativeto the shaft and transition region.
 44. A suturing kit as in claim 40,further comprising needle guide tubes disposed in the entry and exitlumens and means to extend the guide tubes across the gap and to thereturn lumen in the nose piece
 45. A suturing kit as in claim 40,further comprising a drive wheel disposed on the shaft to engage aflexible needle present in the entry lumen, whereby rotation of thedrive wheel advances the needle through the entry lumen, across the gap,through the return lumen, across the gap, and through the exit lumen.46. A suturing kit as in claim 36, wherein the nose piece has asuture-release slot formed contiguously with the return lumen.
 47. Asuturing kit as in claim 36, further comprising means for opening thenose piece to release suture therefrom.
 48. A suturing kit as in claim47, wherein the opening means slides a portion of the nose piece toexpose the return lumen.
 49. A suturing kit as in claim 47, wherein theopening means swings a portion of the nose piece to expose the returnlumen.
 50. A suturing needle comprising: an elongate needle shank havinga sharpened distal tip, said shank being composed of a superelasticmetal alloy; and a length of suture attached to the needle shank.
 51. Asuturing needle as in claim 50, wherein the needle shank has a length inthe range from 10 cm to 30 cm.
 52. A suturing needle as in claim 50,wherein the needle shank is composed of a nickel-titanium alloy.
 53. Asuturing needle as in claim 50, wherein the needle shank has a proximalend and a sharpened distal tip, and wherein the suture is attached to aproximal end of the shank.